1. Field of the Invention
The present invention relates to a sample plate in use with a MALDI-TOF (matrix-assisted laser desorption ionization time-of-flight) mass spectrometer, and more particularly, to a sample plate usable for the mass spectrometry of a polymeric material on the order of several hundreds of Da and a method of manufacturing the same sample plate.
2. Description of Related Art
In general, mass spectrometers are analytical instruments that measure the mass of a compound, and more particularly, determine the molecular weight of the compound by charging and ionizing the compound and subsequently measuring a mass-to-charge ratio. Methods of ionizing a compound known in the art include an electron ionization method using an electron beam, a method of colliding high-speed atoms against each other, a method using a laser, and the like.
The method of using a laser among these methods includes mixing an ionization-assisting matrix with a compound (sample), forming a target including the mixture, and radiating a laser beam onto the target. This method ionizes the sample using the characteristics of the sample in that it is easily ionized with the assistance of the matrix. It is advantageous in that this method can measure the molecular weight of a polymeric material, analyze a sample on the order of peptomol due to high sensitivity, and significantly reduce the phenomenon in which a compound to be analyzed is fractured during ionization. Therefore, the MALDI-TOF mass spectrometry using a laser is effective for biochemical materials having a large molecular weight such as proteins and hexanes, and MALDI-TOF mass spectrometers are currently being commercialized.
However, this method has a drawback in that different matrix materials must be determined depending on the types of samples since the samples are ionized using a matrix. In addition, a typical matrix material has a molecular weight of hundreds of Da. When the molecular weight of a compound to be analyzed is similar to that of the matrix material, the mass spectrum reflects the decomposed matters of the matrix material. It is therefore difficult to use the MALDI-TOF mass spectrometry for compounds having a molecular weight of hundreds of Da.
In order to overcome these problems, a MALDI-TOF mass spectrometry using a metal nanowire instead of the matrix was proposed, for example, in Korean Patent Application Publication No. 10-2005-92809 and 10-2012-95638. The MALDI-TOF mass spectrometry using the metal nanowire is based on the principle of forming nanowire spots by growing a plurality of nanowires on a specific area of a conductor or semiconductor substrate, placing a compound (sample) to be subjected to mass spectrometry on the nanowire spots, drying the compound, and subsequently transferring energy to the sample through the nanowire by radiating a laser beam onto the nanowire spots, such that the sample is attached/detached and ionized.
However, when this method is used, the nanowires are grown by blowing a material to be grown into the nanowires as a vapor precursor along with a high-temperature and high-pressure carrier gas onto a metal catalyst on the substrate. This method is commonly referred to as vapor liquid solid (VLS) synthesis. However, the process of placing an array of metal catalyst on the substrate must be performed in advance in order to form a nanowire array using the VLS synthesis. However, the process of placing an array of metal catalyst has a high degree of difficulty and thus is rarely applied to mass production. In addition, the VLS synthesis is carried out within a high-temperature and high-pressure quartz tube, thereby increasing manufacturing costs and making mass production difficult.
The information disclosed in the Background of the Invention section is provided only for better understanding of the background of the invention and should not be taken as an acknowledgment or any form of suggestion that this information forms a prior art that would already be known to a person skilled in the art.